Screw-propeller.



No. 701,242. Patented May 27, 1902.

J. AEGERTER.

SCREW PROPELLER.

(Application filed Sept. 4, 1900.) (HQ Model.) 2 Sheets-Sheet 2.

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I UNITED STATES PATENT FFICE.

JACOB AEGERTER, OF SAN FRANCISCO, CALIFORNIA.

SCREW-PROPELLER.

SPECIFICATION forming part of Letters Patent No. 701,242, dated May 27, 1902.

Application filed September 4, 1900. $erial No. 29,006. (No model.)

To all whmn it may concern:

Be it known that I, JAooB AEGERTER, a citizen of the United States, residing in the city and county of San Francisco and State of California, have invented certain new and useful Improvements in Marine Propulsion; and I do hereby declare that the following is a full, clear, and exact description of myinvention, which will enable others skilled in the art to which it appertains to make and use the same.

Myinvention relates to screw-propellers, particularly to the blades of same, which consist of semicircular flanges projecting downwardly at the ends of the hub, and to the uniform construction of same, as will be more fully described hereinafter.

The object of my invention is to increase the bearing-faces of the blades, particularly at their ends, so that a similar force of propulsion can be obtained while moving either forward or backward and at the same time reduce the centrifugal pressure of Water around the hub.

Referring to the accompanying drawings, which form part of this specification, Figure 1 represents a perspective view of my improved propeller. Fig. 2 is a vertical side elevation of one of the blades, showing particularly the form of construction of same; and Fig. 3 is a top view of Fig. 2, showing the curvature as it appears when looking downwardly.

Similar letters refer to similar parts throughout the drawings.

A represents the hub of my improved propeller, which may beadjustedto the shaft B in any suitable manner. Mounted diagonally upon the hub are my improved blades 0, which are preferably two in number and secured opposite each otherin a parallel curved line. One of theseblades is particularly illustrated in Fig. 2, which consists of a semicircular flange having the ends a a formed substantially alike and projecting downwardly at the ends of the hub, and has a narrow shank or base I) integrally formed upon the hub. Between the center of the projecting ends a a of the blades and the ends of the hub, respectively, are curves cut inwardly upon the sides of the base I) and the blade to form the opening 0 near the hub. \Vhen constructed in this manner, the water, which may be forced centrally by the movements of the blades, will find its way out through the opening 0, thus releasing the pressure of water around the hub.

Ihave shown in Fig. 3 the curvature of the blades, which have their lobes twisted according to the pitch-line of a screw or spiral and arranged upon the hub in such manner that the ends of each blade project downwardly at the ends of the hub. Thus constructed I obtain a continued propulsion force while in motion.

Believing I have produced a novel and useful means of propulsion and having described same, what I claim, and desire to secure by UnitedStates Letters Patent, is

1. A propeller-blade consisting of semicircular flange having uniform shape mounted diagonally upon suitable hub and projecting at its ends downwardly beyond the center of the hub, substantially as set forth and for the purpose specified.

2. A propeller composed of two blades mounted upon a suitable base and diagonally thereof, said blades being so constructed as to provide the openings 0 substantiallyaround the hub, for the purpose specified.

3. A reversible propeller composed of two semicircular blades provided with bases mounted upon suitable hub, and having their ends formed substantially alike and provided with inward curves at each end of the base thereof, as set forth and for the purpose specified.

4. Inapropeller having semicircular blades provided with suitable bases mounted diagonally upon the hub, inward curves formed substantially alike at the center of the blades near the hub, as set forth and for the purpose specified.

5. A propeller composed oftwo blades provided with suitable bases mounted upon the hub, having downwardly prOjeeting ends formed substantially alike and inward curves made between the centerofthe projecting ends of the blades and the hub, as set forth and for the purpose specified.

6. In a reversible propeller, semicircular blades having narrow shanks or bases mounted diagonally upon suitable hub and project ing at their ends downwardly toward the conter of the hub at its ends and inward curves formed at the center of the blades adjoining the base portion, substantially as set forth and for the purpose specified.

7. In a reversible propeller, blades c0nsisting of semicircular flanges of uniform shape, having suitable bases mounted diagonally upon suitable hub, and projecting downwardly at their ends beyond the ends of the hub, inward curves formed substantially alike between the center of the extreme ends of the flanges and the hub, as set forth and for the purpose specified.

'8. A propeller composed of a hub, two blades mounted thereon and having downwardly-projecting ends, so as to provide aseries of openings, substantially around the hub for the purpose specified.

In testimony whereof I have aflixed my signature, in presence of two witnesses, this 28th day of August, A. D. 1900.

L. MEININGER, J. CoRINsoN. 

